Longitudinally elongated electrically conductive lines are one type of component used to interconnect devices in integrated circuitry. Such may be formed by subtractive patterning and etch of conductive material. Alternately, a trench having a desired longitudinal outline of the conductive line may be formed in semiconductive or other material. Then, the trench may be wholly or partially filled with conductive material. The conductive material received laterally outward of the trench is then removed.
In some instances, the conductive material within the trench from which the line is formed may be recessed, for example by etching. Insulative material is ultimately provided within the trench over the recessed line, as well as over the substrate material within which the trench was formed. Such may occur with multiple depositions and processing steps that form other device components over or laterally spaced from the recessed line that is received within the trench.
Electrical connection is ultimately made to the recessed line and to other devices which are laterally spaced there-from. For example, contact openings are etched through the insulative material to the outermost surfaces of the recessed lines and other devices, with such openings subsequently being filled with one or more conductive materials. The outermost conductive surface of the recessed line may be received considerably deeper within the substrate than is the outermost conductive surface of other device components that are laterally spaced from the recessed line. Accordingly, there is risk of over-etch into the conductive portions of these other device components while continuing a contact etch through insulative material to reach deeper to the recessed line. Such is accommodated for in the prior art by conducting at least one or more mask and etching steps for different elevation devices that are elevationally higher or outward of the recessed conductive lines.
While the invention was motivated in addressing the above identified issues, it is in no way so limited. The invention is only limited by the accompanying claims as literally worded, without interpretative or other limiting reference to the specification, and in accordance with the doctrine of equivalents.